1. Field of the Invention
The present invention relates to a monolithic ceramic electronic component, in particular, to a monolithic ceramic electronic component in which an outer electrode that is connected to electrode layers such as inner electrodes located along ceramic layers includes a plating film and the plating film is directly connected the electrode layers.
2. Description of the Related Art
An outer electrode of a monolithic ceramic capacitor, which is an example of a monolithic ceramic electronic component, is usually formed by applying a conductive paste onto an end portion of a component body, and baking the conductive paste. However, an outer electrode formed by this method has a large thickness of several tens to several hundreds of micrometers. Accordingly, in order to control the dimensions of such a monolithic ceramic capacitor so as to be within certain specified values, it is necessary to undesirably reduce the effective volume for securing the electrostatic capacitance by an amount necessary to secure the volume of the outer electrode.
As a technique that can solve this problem, it has been proposed that a plating film be deposited directly on a component body so as to connect extending ends of a plurality of inner electrodes to each other and the plating film be used as at least a portion of an outer electrode. This technique has been put into practical use. For example, Japanese Unexamined Patent Application Publication No. 63-169014 discloses a method for forming an outer electrode, the method including depositing a conductive metal layer by electroless nickel (Ni) plating over the entire sidewall surface of a component body on which inner electrodes are exposed so that the inner electrodes exposed at the sidewall surface short-circuit each other. According to this method for forming an outer electrode, the volume of the outer electrode can be reduced, and consequently, the effective volume for securing the electrostatic capacitance can be increased.
However, the outer electrode formed by this method has the following problem. In the above-described case where an electrode is formed by baking a conductive paste, the conductive paste is fixed to a component body with glass or the like interposed therebetween. On the other hand, in the case where a plating film is formed directly on a particular surface of a component body by plating, the plating film is fixed to the component body without providing glass or the like therebetween. Therefore, the fixing force between the plating film and the component body is weak, and the plating film, that is, the outer electrode is easily separated from the component body.